With Porto Alegre recording its wettest September since 1916 and São Paulo its hottest September in 80 years, the month will end on a high note, with New York completely submerged by a wellabovenormal storm.
Car on flooded street in New York due to the 29/29/923 storm
(Photo: MTA New York City Transit Marc A Hermann 9/29/23 Public Photos)
New York, one of the most important cities in the world, was defenseless against the colossal amounts of rain that fell on September 29, 2023. Flooded streets and neighborhoods, flooded highways, flooded airports. New York’s subway system experienced widespread problems because it was inundated by waterfalls running down the stairs. People are stranded, cars are floating.
Due to the storm this Friday, September 29th, New York is experiencing its second lowest September on record with nearly 350 mm (13.74 inches) of rainfall. However, this value is provisional and is expected to rise as rain continues for over 24 hours this Friday and part of Saturday, September 30th.
Governor Kathy Hochul declared a state of emergency and called on the population to stay at home in view of the completely chaotic and dangerous situation in New York and the surrounding regions.
Thunderstorm in New York 9/29/23 MetroNorth View of the Lakeview Road intersection on the Harlem Line
(Photo: MTA New York City Transit Public Photos)
Fox5 News from the United States reported that this Friday, September 29, 2023, was the rainiest day in New York since September 1, 2021, when it received 7 inches (177.8 mm) in 24 hours during Hurricane Ida. rained.
How much did it rain in New York?
According to the NWS, the United States National Weather Service, the JFK airport area received 154.4 mm (6.08 inches) of rain in about 12 hours from midnight to just after noon (Brasília time). The previous record was 148.1 mm (5.83 inches) on December 9, 1960. Registration at JFK began in 1948.
(In the English news about the storm in New York you will find the word “inch”, or “in” for short, which means “inch”, and in Portuguese; 1 inch or 1 inch is equal to 25.4 mm of rain)
In the area of La Guardia International Airportwhich is located in Queens, 9 miles from central New York, it was raining 217.9mm in less than 24 hours (8.58 inches), with the average normal precipitation for the entire month of September being 98.5 mm (3.88 inches), according to NWS calculations for the period 1991 to 2020.
The map obtained from the NWS website spatially shows the amount of rain that fell over the New York region and other nearby areas.
Accumulated rain in the New York region in 24 hours as of 6 p.m. (local) on 09/29/23 (Source NOAA/NWS)
In More than 100 mm has accumulated in less than 24 hours in several parts of the city at the same time, and that is more than average rainfall for the entire month of September. According to the NWS, the normal average rainfall for September in the JFK Airport area is 90.9 mm. In the La Guardia airport region, this average is 98.5 mm.
New York is a metropolis with several infrastructure problems common to a large city that do not appear in films or travel programs, and it could not withstand so much rain.
Precipitation totals in New York on 29,923 (preliminary)
Check out other very high rainfall totals recorded in the region near New York, in the states of New Jersey and Connecticut (Source NWS via FOX5).
In New York, the Queens and Bronx regions recorded the highest amounts of rain.
Bronx
Fordham 6.26” 159.0mm
Harlem 5.37 inches 136.4 mm
Kings Brooklyn 7.21 inches 183.1mm
South Slope 7.18 in. 182.4 mm
Prospect Park 6.66″ 169.2mm
1N Bay Ridge 6.28 in. 159.5 mm
Brooklyn College 5.59 inches 142.0 mm
New York (Manhattan)
Midtown Manhattan 6.16 inches 156.5 mm
Central Park 5.85 inches 148.6 mm (September average = 109.5 mm)
Manhattan 4.66 inches 118.4 mm
Queens
JFK Airport 8.58 inches 217.9 mm (Average for September = 90.9 mm)
Ozone Park 7.15″ 181.6mm
Bellerose 6.66 inches 169.2 mm
Kew Garden Hills 6.14″ 155.9mm
La Guardia Airport 4.87 inches 123.7 mm (September average = 98.5 mm)
Richmond
Staten Island 3.32 inches 84.3 mm
Westchester
New Rochelle 5.87 inches 149.1 mm
Connecticut
Fairfield
Greenwich 5.04 inches = 128.0 mm
New port
Waterbury Airport 3.58 inches 90.9 mm
New Jersey
Bergen
1 SSE Franklin Lakes 3.64″ 92.5mm
Hudson
Hoboken 3.48 inches 88.4 mm
What caused so much rain in New York?
The reason for the extreme rainfall in the New York region was a cold front that brought low pressure but slow movement.
Rain over NY GOES East Satellite NOAA 09/30/23 6:46 AM UTC
The image below shows the synoptic map of the United States as of the morning of September 29, 2023, showing the weather systems that impacted the country. This type of map is created in all meteorological centers around the world and summarizes the actual situation of the atmosphere at the Earth’s surface.
New York felt the influence of the stationary cold front, with the center of low pressure over the New Jersey region.
Synoptic map shows weather systems across the United States on the morning of 9/29/23 (Source: NWS)
About the symbols in the overview diagram
The letter L (from low) indicates a center of low air pressure, which in Brazil would be a red B. At low pressure, moisture accumulates, resulting in heavy cloud cover and rain.
The letter H (from high) indicates a center of high atmospheric pressure, which in Brazil would be a blue A. High pressure reduces humidity, which reduces cloud cover and the chance of rain.
The colors blue for “high” and red for “low” are international conventions adopted by the World Meteorological Organization.
The curved lines with a blue triangle (ria front) and red crescents (warm front) between them represent stationary cold fronts; dashed brown lines are atmospheric troughs, a region where winds tend to move counterclockwise in the Northern Hemisphere (clockwise in the Southern Hemisphere).
The center of the low pressure and stationary cold front that caused the torrential rain over New York is moving away from the coast across the Atlantic this Saturday.